Although a considerable body of research indicates that prison-based treatment followed by continuing treatment in the community is effective in reducing drug abuse and crime among drug-abusing offenders, the impact of providing treatment is less than optimal because offenders often fail to follow through on treatment referrals, leave treatment early, or have poor engagement in treatment activities. In particular, participation in prison-based treatment alone is seldom effective in reducing drug use or recidivism unless it is followed by participation in community treatment. For correctional systems that provide a continuum of care model from prison to community, low rates of admission and retention result in poor outcomes and poor resource utilization. One way to address this problem is to provide incentives to parolees for community treatment participation. Although research supports the effectiveness of behavioral reinforcement, mainly in the form of contingency management (CM), for general substance abuse populations, CM has not yet been tested or adapted for use in community-based programs for offender populations, particularly to encourage treatment attendance. The UCLA Integrated Substance Abuse Programs (ISAP), in collaboration with Walden House and the California Department of Corrections and Rehabilitation, is proposing a five-year health services research study that will involve a randomized test of the use of incentives with parolees in a community-based TC to increase treatment admission and treatment retention, and thereby increase the likelihood of improved outcomes. Study participants will be recruited from clients in a prison-based treatment program who have a referral to the Walden House community program. The Admission Phase of the study assesses the effect to fan incentive (voucher) on enrolling in the Walden House program. The Attendance Phase assesses the effect of incentives on treatment attendance and on post-treatment drug use, crime, and psychosocial behaviors. The intervention will last for six months. Study participants will be interviewed at baseline and at 12 months following the intervention. Treatment and criminal justice data will be obtained. Data on acceptability, satisfaction, and sustainability will be collected from focus groups with staff and clients. The study has four specific aims: (1) Determine whether offering an incentive (voucher) increases admission to community treatment by parolees who have participated in prison treatment. (2) For parolees who enter community treatment, determine whether providing incentives for attendance results in greater retention in treatment. (3) Assess the long-term impact of the use of incentives on drug use, crime, and psychosocial outcomes at 12 months following the end of the six-month intervention. (4) Assess issues of acceptability, satisfaction, and sustainability of the use of incentives to increase admission and retention among staff and clients.